I've just posted a pre-release of Firefox Portable 2.0. This release has many of the same features of Firefox Portable 2.0 RC3. There are a couple additions:
License Agreement Added - The Mozilla Firefox 2.0 end user license agreement is now displayed on first run.
Vista Compatibility - Both the launcher and the installer are now compatible with Windows Vista and should install and run even on a Guest-level account.
As for testing, I'd like to get some folks testing out the license agreement when using an INI as well as when running from CD as I haven't put it through as thorough testing in these scenarios.
I'm still debating adding in a prompt on first run on whether to enable session saving. On some slower drives, it slows down Firefox quite a bit. Any thoughts on this are welcome as well.